Turned-off iPhone racks up $1,106 in charges abroad

You know the zombies that pop back to life even after you stab them with a pitchfork? It’s the same with smartphones.

That’s the bitter lesson learned when I returned home from a trip to Greenland to get a $1,106 bill from Sprint for international data roaming — even though data roaming on my personal iPhone 4S was turned off.

How could this zombie data usage happen?

Smartphones are the undead of phones. They keep looking for a way to connect to data, even when you don’t want them to. Even when you think data is turned off.

You have heard the horror stories: A woman gets a $201,000 data roaming bill when her brother uses a smartphone in Canada. A man gets a $22,000 bill when his child turns on a movie and watches it on the phone on a family vacation in Jamaica.

I had a BlackBerry before my iPhone and never had a single data charge when traveling internationally.

But data-rich smartphones are different. Data roaming may be turned off, leaving only voice roaming active so you can call home. But if the phone keeps trying to connect to data, it may succeed. Possible scenarios:

—A smartphone’s location services, push notifications or apps switch data roaming back on beneath the surface while the customer is clueless.

—You decide to use free Wi-Fi for a minute, not realizing that on some phones if the Wi-Fi signal is even briefly interrupted your phone will connect to the Web via the costly foreign 3G network.

—Phones turned off may reinstate obscure underlying data roaming features when switched back on.

After throwing myself on Sprint’s mercy, they checked my longtime customer status and trimmed the roaming charge by 75 percent.

I thought that was a good result — until I found out that according to a 2010 agreement with the FCC, America’s wireless carriers are required to combat cellphone “bill shock” by notifying customers via voice or text as soon as international roaming, text or data charges begin to mount — not after the damage has already been done.

The deadline for full implementation of these rules is April 17, but international roaming warnings are already in effect. All carriers must comply; for example, here is Sprint’s policy: “Sprint sends notifications in approximately $50 increments of international data roaming charges. Casual international roaming users will be required to opt-in when usage charges meet or exceed approximately $100 and (again at) $300.

“All customers incurring approximately $500 of international data usage charges will be suspended. Sprint will continue to send notifications at approximately $50 increments over $500.” (( www.sprint.com/useagealerts.)

The only notification I got was four days after I’d left Greenland and was home. Even then, it warned only that my phone had incurred “at least $103” of data roaming charges.

When did I hear of the $1,106 tab? Two weeks later when the bill came.

Unless you are a technical genius, there are only three options to reliably avoid international data roaming charges:

—Leave your phone at home. If you need one, buy a cheap international phone when you get to your destination.

—Use your smartphone in “airplane mode” only — and I mean, ONLY. That disables phone, text and data but allows you to use the phone as a little computer to hook up to Wi-Fi. Before leaving home, download Skype or Google Voice apps to enable you to call or text through Wi-Fi on your phone. The downside is that you can’t use your phone to make a call unless Wi-Fi is available.

—Call your wireless provider before taking a trip, even to Canada. Ask them to explain policies and disable international data roaming. In addition, manually turn off the cellular network, location services, push notifications, fetch-data feature and email on your phone.

Still, be careful. Monitor your usage.

You never know when that sleeping zombie’s eyes will fly open, spin like pinwheels and wake the data.